Friction-clutch



(N0 Modem J. W. BLODGETT.

FRICTION CLUTCH;

No. 339,259. Patented Apr. 6, 1886.

wumo m hw. Wnidngton. n. c.

lUi irnn tirarns ATENT Orricn.

JOHN IV. BLODGETT, OF HIGHIVOOD, ASSIGNOR OF OXE-HALF TO FRANKLIX M.BLAIR, OF CHICAGO, ILLINOIS.

FRICTION-CLUTCH.

@PECIFICATION forming part of Letters Patent No. 339,259, dated April 6,1886.

Application filed September 7, 1885. Serial No. 176,439.

To (I/ZZ whom it may concern.-

Be it known that I, JOHN W. BLODGETT, a citizen of the United States,residing at Highwood, in the county of Lake and State of Illinois, haveinvented certain new and useful Improvements in Friction-Clutches, whichare fully set forth and described in the annexed specification,reference being had to the accompanying drawings, in which Figure 1represents a front elevation of a shaft and crank-arm with myfriction-clutch applied; Fig. 2. a similar view with crank arm removed;Fig. 3, a reverse elevation of the crank-arm detached; Fig. 4, across-section taken on the line x m, Fig. 1; Fig. 5, a dc tail view ofthe clutch eccentric ring detached, and Fig. 6 a similar view of theeccentric wedge against which the ring acts.

My invention relates to an improvement in the construction and operationof frictionclutohcs, whereby a certainty and quickness of action areobtained, and there is little or no effect from wear.

I will now proceed to describe in detail one way in which I have carriedout my invention in practical form, and will then point out definitelyin the claims the special improvements which I believe to be new, andwish to protect by Letters Patent.

In the drawings, A represents one end or some other part of a shaft, towhich is secured in any suitable way a cup-shaped disk, 13. The flangeI) of this cup-disk is perpendicular to the body, and on the same sideof the latter is a boss, I). centrally arranged and fitted to the shaft.The cup may be attached to the shaft through the boss or otherwise.

The eccentric ring O is fitted to the exterior of the boss I), thecircumference of the latter being a true circle having the same centeras the shaft. This ring is provided on one side or face with a shortprojecting stud or pin, 0, as shown in Fig. 5 of the drawings, whichalso illustrates the varying width of the ring, by which its outercircumference is made eccentric as to the center of its central Opening.

An eccentric wedge or clamp, l), is fitted within the cup between theflange and boss. This piece is the segment of a ring, the outer (Nomodel.)

circumference of which is the same as the inner circumference of theflange, and in the drawings this segment is shown as about onehalf ofsuch a ring. The width of this seg ment is not sufficient to fill thespace between the flange and the boss; but it doesnearly or quite fillthe space between the flange and the eccentric ring when the latter isplaced on the boss. In fact, it is wider than the space be tween theflange and the widest portion of the eccentric ring, but not quite sowide as the distance between the flange and the narrowest part of saidring. The internal circumference of the segment is a circlecorresponding to that of the exterior circumference of the eccentricring, so that the exterior surface of the latter will fit the wholelength of the inner surface of the segment, while the outer surface ofthe segment along its entire length fits the inner surface of thedislcflange. The position of these parts within the cup and theirrelation to each other are clearly shown in Fig. 2 of the drawings. Thesegment D is made slightly tapering in width from its heel end (I, sothat its front end, (1, is the narrowest portion of the entire piece. Aslight recess, al is made in theheel end of the segment, which is placedloosely within the cup, setting loosely between the flange of the latterand the eccentric ring, which is also placed loosely on the boss.

It is obvious from an inspection of Fig. 2 of the drawings that if theeccentric ring he turned in the direction of the arrow its wideningportion willbe drawnin against the inner circumference of the segmentalclamp by reason of the increasing width of the ring and the decreasingwidth of the space between the boss and the segment. At the same timethe segment is forced out firmly against the flange of the cup, and soit is evident that by the frictional contact between the surfaces of theboss, ring, segment, and flange the ring and cup will be secured to eachother, so that one must turn with the other. It is also evident that byturning the ring slightly in the other direction the friction betweenthese surfaces will be relieved or entirely removed, if the backwardmovement of the ring is made sufficient. An eccentricity in the ring ofabout one-fortieth of an inch to one and one-fourth inch of the insidediameter of the cup is well adapted for this use.

Now, suppose E to bea cranl -arm to which a pitman or some other deviceis to be' connected for giving the required movement to some piece ofmachinery. This arm is either attached to or made in one piece with asimple disk, F, which is adapted to entirely cover the cup B, beingfitted to the outer edge of its flange b. At a suitable point in thisdisk is an aperture, f, which is adapted to receive the pin on theeccentric ring, thereby connecting the latter with the disk andcrankarm. The cover-disk is also fitted to the boss I), which projectsbeyond the cup-flange somewhat, as shown in Fig. at of the drawings,"for this purpose, the disk being provided with a central opening, f,adapted to receive the boss. The cover disk is held in place by means ofwasher and nut G on the shaft, or by any other suitable devices, thedisk, however, beingleft free to turn on the boss. On t-he inside of thecover-disk isa spiral spring, H, surrounding a curved rod, 71, which isfastened at one end to the disk, but is free at the other to permit themovement of the spring when it is compressed or recoils, the free end ofthe spring extending somewhat beyond the free end of the rod in itsnormal condition, as shown in Fig. 3 of the drawings. This spring isarranged on the disk opposite to the aperture f, which receives the pinof the eccen tric ring, and when the cover is applied the free end ofthe spring is intended to rest in the recess at the heel end of thesegmental clamp. The effect of this spring is twofold: it provides anelastic resistance to the back ward movement of the segment when thering is turned forward to clamp the parts together, thereby preventingthe segment from slipping around under the action of the ring. There isnot much danger of this movement, however, as the frictional surfacesare so large that the wedging or clamping effect is quick and certain.When the diskcover is turned back, thereby turning the eccentric ringback, the spring also carries the segment around in the samedirection,'thereby causing the segment to follow up the eccentric ring,so that it will always be in position for the quick engagement of thering when the latteris turned forward. It is also evident that this movement permits the ring to be carried entirely around its journal, whichwould not be possible if the segment remain stationary when the ring isturned back. It is obvious that the crank being a part of or connectedto the cover-disk, its movement will impart a like movement to the disk,and through the latter.

to the eccentric ring, so that when the crank is turned in one directionit will be clutched to the shaft and rotate the latter; but if turned inthe opposite direction it will be un' clutched therefrom and move aroundwithout moving the shaft.

with the devices constructed and arranged substantially as describedabove, I obtain a friction-cl utch which is very quick in actiou,for thereason that the segment follows closely the movement of the ring, and soa slight turn forward of the latter produces at once a clamping effect;also a clutch that is very certain in its action, for the reason thatthe frictional surfaces are of considerable extent, and for the samereason the clutch is very strong. It will also be seen that as the partsof the clutch are all circular and the contact-surfaces are broughttogether on the arcs of circles the clutch will not be impaired byordinary wear, which will be readily compensated by the form of theparts, and in use the wear will be neeessarily slow because of the largefrictional surfaces. There is no biting effect or unequal wear-such asresults from the use of small rollers or balls, which have sometimesbeen employed for this purpose-and there are no parts to be moved byspecial devices to effect a clamping operation. The clutch is entirelyautomatic and always ready for action.

I do not wish to be understood as limiting myself to the cdnstructionand arrangement of devices precisely as herein shown and described, forit is evident that changes may be made in details of constructionwithout departing from the essential characteristics of my invention,and, in fact, such changes will be a necessity in applying theimprovement to different mechanisms and in different locations.

In the drawings and description above I have intended to illustrate anapplication of my improved clutch, and only this.

I do not wish to be understood as hereshowing the exact and onlyconditions under which my improvement is to be applied.

It is obvious that this clutch is applicable in a great many placeswhere other clutches are used, and I wish to be understood as claimingit wherever it may be applied and with whatever changes may be necessaryin making different applications thereof.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, 1's- 1. In a friction-clutch, a cup attachedto one of the moving parts, in combination with an eccentric ringmovable about the center of the cup and connected to the companionmoving part, and a ring-segment arranged loosely between the eccentricring and the flange of the cup, substantially as and for the purposesset forth.

2. The disk B, provided with the flange 1) and central boss, I), incombination with the eccentric ring 0, mounted loosely on the boss, andthe loose ring'segment D, fitting against the flange on its exteriorsurface, and the eccentric ring on its interior surface, substantiallyas and for the purposes set forth.

3. The eccentric ring 0, provided with a stud, c, in combination withthe cover-disk F,

provided with an aperture, f, to receive the .3. The cup-disk B, incombination with the 10 stud, substantially as and for the purposes seteccentric ring 0, thering-segment D, the cover forth. F, and the springH, substantially as and for 4. The cup-disk B, in combination with thethe purposes set forth.

eccentric rim O, the loose ring-segment D, T H

5 the cover-disiz F, to which the eccentric ring 70H; BLODGET'L isconnected, and a follower connected to the Witncsses: cover and arrangedbehind the ringsegnlent, \V. G. CORLIES, substantially as and for thepurposes set forth. G. FEIGEL.

